A deputy prime minister said 45 of 50 polling stations in the capital had been closed down and advance voting was disrupted in 10 of Thailand's 76 provinces.

On Saturday, a government minister said Prime Minister Yingluck Shinawatra was prepared to discuss cancelling the Feb. 2 election if activists ended more than two months of often unruly protests. The government said it was ready to delay the vote if its opponents agreed not to boycott or disrupt a rescheduled poll.

Yingluck called the Feb. 2 election in the hope of cementing her hold on power in the face of the disruption.

"Protesters blocked voters. In many areas of Bangkok protesters used force to prevent people from voting," Foreign Minister Surapong Tovichakchaikul, also a deputy prime minister, said in a televised address.

"This is a very serious offence indeed."

Yingluck's government had warned anyone who tried to stop voting would face jail or fines, or both.

Any delay in the poll will do little to quell the resolve of protest leader Suthep Thaugsuban, a former deputy prime minister, who has rejected elections, and is unlikely to provide a quick resolution to the current deadlock.

It was already unclear whether the election would go ahead after a Constitutional Court added to the pressure on Yingluck on Friday with a ruling that opened the possibility of a delay.

The government declared a 60-day state of emergency, in effect from last Wednesday, to try to curtail protests. While mainly peaceful, nine people have been killed and scores wounded in sporadic violence.

The protesters had vowed to shut down Bangkok - the world's most visited city in 2013 - on Jan. 13 and have since occupied key intersections, disrupting some aspects of daily life.

The protests are the latest eruption in a political conflict that has gripped Thailand for eight years and which is starting to hurt growth and investor confidence in Southeast Asia's second-largest economy.

The conflict broadly pits Bangkok's middle class and elite, and followers in the south, against mainly poor rural backers of Yingluck and her brother, ousted former premier Thaksin Shinawatra, in the populous north and northeast.

The protesters accuse Yingluck of being the puppet of her brother, who lives in self-imposed exile after a 2008 graft conviction he says was politically motivated.

They say Thaksin's powerful political machine has subverted Thailand's fragile democracy by effectively buying the support of rural voters with populist policies such as cheap healthcare and subsidies for rice farmers.

POTENTIAL VIOLENCE

The Election Commission has also called for a delay, saying Thailand is too unsettled for a vote to proceed. The protesters want an unelected "people's council" installed to oversee a period of reform before any future vote is held.

City officials said they had begun negotiating with the protesters. "We have to negotiate with them and let them know that blocking the election is illegal," said Luckana Rojjanawong, director of Ratchathewi District Office in Bangkok.

Paul Chambers, director of research at the Institute of South East Asian Affairs in northern Chiang Mai, said the disruption of advance polling would add impetus to the calls for an election delay.

"The ability of those against advance voting to keep it from happening today could signal what may come next week - a decision to delay the vote due to an inability to hold the election properly," Chambers said.

He said delaying the vote would at least defuse tensions temporarily. "It clearly can't take place, for the most part in Bangkok and the south, and there could be a lot of costs, including violence and waste of tax payers' money," he said.

Yingluck, who would probably win an election easily, is set to meet Election Commission officials on Tuesday. The main opposition Democrat Party has said it will boycott the election.

About 49 million voters, out of Thailand's population of 66 million, are eligible to cast ballots. About 2.16 million registered for advance polling.

Yingluck's government had been proceeding relatively smoothly until her Puea Thai Party miscalculated in November and tried to force through an amnesty bill that would have allowed her brother to return a free man.

Thaksin, a billionaire former telecoms tycoon, was ousted by the military in 2006 amid charges of corruption and disrespect for Thailand's country's revered monarchy. (Additional reporting by Aukkarapon Niyomyat and Jutarat Skulpichetrat; Editing by Paul Tait and Ron Popeski)

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